Process for producing plastic cards

ABSTRACT

The invention relates to a method of producing plastic cards with a layer structure, in each of which cards a flat coil and a chip which is connected thereto are embedded, these components being placed on a first web, to which a subsequent web for accommodating apertures for the components and at least one covering web are applied, which webs are then joined together by lamination so as to form a final web, out of which plastic cards are stamped. In order to simplify such a method, it is envisaged that a second web, which is placed on the first web, is held on a selectable web section of the latter by means of fixing points, while an aperture which is to accommodate the flat coil is made in the second web, for which purpose the fixing points are distributed in such a manner that they are arranged on both sides next to a part of the web which corresponds to a shape of the flat coil, and then the flat coil, in order to be placed on the first web, is inserted into the aperture formed in this way and the chip is inserted into a web which is provided with a chip opening.

The invention relates to a method of producing plastic cards inaccordance with the preamble of patent claim 1.

A method of this kind is known from DE 195 09 233 A1. According to thismethod, first of all a first web is provided with electronic componentsin the form of a chip with a prefabricated flat coil which can beconnected to it and has a plurality of windings. It is sensible to applythe electronic components, with which this first web is fitted, inadvance, so as to form a so-called carrier web. The components arepreferably attached by means of an adhesive. The carrier web which hasbeen prefabricated in this way is then supplied to a method of producingchip cards in which this carrier web is incorporated into a layerstructure comprising a plurality of webs. To do this, a second web whichhas apertures for accommodating the electronic components is applied tothe carrier web. Then, in a further method step, filler material isintroduced into the apertures and smoothed down. A covering web which isprovided on at least one side completes the layer structure which isultimately to be laminated. The effort involved in prefabricating thewebs is high. Furthermore, this prefabrication does not allow anydifferent arrangement of the electronic components in a chip card.

WO 96/10803 has disclosed a carrier arrangement which is to be installedin a contactless chip card, in which an endless carrier film is providedwith a layer of adhesive to which a multiplicity of transponder unitscontaining a chip and a coil are applied. This arrangement ishermetically packaged by means of a covering film, cutouts in thecovering film advantageously being provided in the region of thesemiconductor chips. The carrier arrangement comprising transponderunits packaged between two films is advantageously wound onto a roll inorder to be transported further. In this case too, the need toincorporate a prefitted carrier web is a disadvantage.

To create space in a card body for accommodating the coil and the chip,it is also impossible to hot-press a recess in the case of materialwhich is in the plastic state when warm, such as polyvinyl chloride,since the surface would swell locally and a printed image which may bepresent on webs laminated on would become distorted.

Therefore, the object of the invention is to provide a method ofproducing plastic cards according to the preamble of patent claim 1which operates with a high throughput, a low outlay on machinery and alow reject rate.

The solution according to the invention to this object is defined bypatent claim 1. The other claims relate to advantageous refinements ofthe concept of the invention.

The result is a method which avoids having to incorporate prefittedcarrier webs. Rather, the fitting of the components is integrated in theproduction process of the chip cards. Matching and alignment problemscaused by prefabricated carrier webs are eliminated. It is also possibleto separate out defective electronic components without also having toget rid of sections of web.

Spots of adhesive or weld spots may be used as the fixing points. Sincethe number of fixing points can be selected to be low, according to themethod of the invention, the spots of adhesive or weld spots do notinterfere with the subsequent lamination operation.

If spots of adhesive are used as the fixing points, it is possible, byselecting a suitable adhesive, for the adhesive effect at a spot ofadhesive to be exerted repeatedly. This allows first spots of adhesiveto take on a dual role, namely to temporarily fix a stamped-out part ofthe web and, after this part of the web has been removed, to secure aflat coil which is inserted into the area where the piece of web hasbeen removed. So-called autoadhesive agents are preferred.

Further features and advantages of the invention will emerge from thefollowing description of an exemplary embodiment, in which reference ismade to the appended drawings, in which:

FIG. 1 shows a plan view of part of a first web, before adhesive isapplied, in accordance with a first exemplary embodiment,

FIG. 2 shows the first web in accordance with FIG. 1 after the adhesivehas been applied,

FIG. 3 shows the first web in accordance with FIG. 1 with a second webattached,

FIG. 4 shows the webs in accordance with FIG. 3 following a stampingoperation,

FIG. 5 shows a side view of the webs in accordance with FIG. 3 in afollowing working station for removing a stamped area from the secondweb,

FIG. 6 shows a plan view of the first and second webs with the coil andchip inserted, in accordance with the first exemplary embodiment,

FIG. 7 shows a plan view of a semifinished product comprising first andsecond webs in accordance with FIG. 7, together with a third web,

FIG. 8 shows a section through part of a finished card in accordancewith the first exemplary embodiment,

FIG. 9 shows a plan view of part of a first web before a second web isapplied, in accordance with a second exemplary embodiment,

FIG. 10 shows the first web in accordance with FIG. 9 with a second webwhich is attached by means of weld spots,

FIG. 11 shows the webs in accordance with FIG. 10 following a stampingoperation.

FIGS. 1 to 8 illustrate sections of a method of producing plastic cardshaving a chip and a flat coil which is connected to the chip, inaccordance with a first exemplary embodiment. The flat coil ispreferably one which has a plurality of wire windings.

FIG. 1 shows part of a first web 10. In the exemplary embodiment, thewebs are unwound "endlessly" from reels; it should be noted, however,that the method according to the invention can also be carried out withsingle sheet webs. The first web 10 is provided with equidistantmarkings 12 which allow this first web 10 to be kept in register withfurther webs when producing plastic cards with a layer structure. Themarkings 12 are preferably holes which are formed in a precisionstamping station. The first web has a thickness of, for example, 0.1 mm.An outline 13 of a card which is to be produced is indicated bydot-dashed lines.

The first web 10 is firstly provided with the markings 12 and thenpasses through a station in which adhesive is applied. This ispreferably carried out using the screen printing process. The adhesiveis an autoadhesive agent, a so-called self-adhesive agent, as is used,for example, for price labels and the like. Such an adhesive has along-term adhesive action, i.e. after the adhesive bond has beendetached by the bonded parts being pulled apart, this adhesive is againable to exert an adhesive effect.

Outer spots of adhesive 14, middle spots of adhesive 16 and inner spotsof adhesive 18 are applied to a section of the first web 10 in theregion of the outline 13 of a card which is to be produced, which regioncan be chosen as desired. The middle spots of adhesive 16 aredistributed so as to match a shape of a flat coil 40 which is to beinserted (cf. FIG. 6). Since, according to the exemplary embodimentdescribed here, the flat coil is designed as a ring, the middle spots ofadhesive 16 lie on the circumference of a circle. Four middle spots ofadhesive 16 are preferably provided. The size and shape of the spots ofadhesive can be selected as desired, for example so as to form spots orarcs. However, the spots of adhesive 16 are discrete, individual spotswhich are spaced apart from one another. Not only would it be uneconomicto coat the entire area within the outer spots 14, or even onlyrelatively large parts of this area, with adhesive, but also this wouldcreate a larger area in which the webs are not laminated together,because the adhesive acts as a parting layer.

Additional spots of adhesive, which are formed by outer spots ofadhesive 14 and inner spots of adhesive 18, as seen in the direction ofthe outline 13 of a card, are applied next to the middle spots ofadhesive 16 on both sides. The above statements relating to size andshape of the middle spots of adhesive 16 apply correspondingly to theouter and inner spots of adhesive 14, 18. Since the middle spots ofadhesive 16, as is explained below, are used to secure the flat coil 40,while the outer and inner spots of adhesive 14, 18 are only intended totemporarily secure or fix two webs before these webs are joined togetherby lamination, these spots of adhesive 14, 18 are preferably small.

In a following operation, a second web 20, which has previously beenprovided with markings 22, is guided in register onto the first web 10(cf. FIG. 3). The second web has a thickness which is preferably equalto a thickness of the flat coil 40 which is to be inserted, for exampleof 0.2 mm. An opening 24 for accommodating a chip 42 (cf. FIG. 6) may bemade at the same time as the equidistant markings 22 on the second webor, as an alternative, in a separate operation.

In a subsequent operation, the result of which is shown in FIG. 4, twoconcentric cuts 26, 28 are made only in the second web, by means of astamping tool, preferably by means of a strip steel punch. This stampingoperation serves to form an aperture in the second web 20 in ordersubsequently to accommodate the flat coil 40 and attach it to the firstweb 10 using the middle spots of adhesive 16. The stamping operationtherefore has to follow the shape and size of the flat coil 40. For thispurpose, the circumferential size of and the spacing between theconcentric cuts 26, 28 are matched to the flat coil 40 which is to beinserted. Furthermore, the stamping operation is to be carried out on asection of the second web 10 in that region of the outline 13 of a cardto be produced which has been selected for the arrangement of the spotsof adhesive 14, 16, 18, i.e. the stamping for the aperture of the flatcoil and consequently the cuts 26, 28 surround the middle spots ofadhesive 16. Consequently, the stamping for the aperture lies betweenthe outer and inner spots of adhesive 14, 18.

During this operation for making an aperture in the second web 20 forthe flat coil 40, the second web 20 is fixed to the first web 10 by thespots of adhesive 14, 16, 18. Consequently, the spots of adhesive 14,16, 18 form fixing points which hold the second web 20 in position onthe first web 10 during an operation in which an aperture for the flatcoil 40 is made in the second web 20, i.e. the second web lies on top ofthe first web 10 when the aperture is being made. For this purpose, thespots of adhesive 14, 18 form fixing points which are distributed insuch a manner that they are arranged on both sides next to a part of theweb which corresponds to a shape of the flat coil.

The stamping depth can be accurately maintained, although no damage iscaused if the first web 10 is also cut into. All that is necessary is toensure that it is not cut through completely. After stamping, a ring 30which has been cut out in this way, forming part of the second web 20,is still held on the first web 10 by means of the middle spots ofadhesive 16. A part 32 of the second web 20 which is completelysurrounded by the stamped section and is therefore separated from thesecond web 20 is held in place by the inner spots of adhesive 18.Furthermore, the first and second webs 10, 20 are held together in thevicinity of the outer cut 28 by the outer spots of adhesive 14.

The ring 30, which is delimited by the cuts 26, 28, is then removed fromthe second web 20. To do this, the webs 10 and 20, which are attached toone another, can be guided over a transverse rod 34, as shown in FIG. 5,with the result that the webs 10, 20 undergo a bending process. Thismakes it possible for a stamped-out region to lift up. If the middlespots of adhesive 16 have been distributed so that they are only presentin a punctiform manner, the front 90° sector 36, as seen in theconveying direction, of the ring 30 projects out of the second web 20,since it is not held in place by adhesive over its entire surface, andcan be taken hold of by a hook 38, from which it is then removed bymeans which are not shown. The ring 30 can be lifted off particularlysuccessfully if the spots of adhesive 16 are not arranged at the top andbottom of a longitudinal axis of a card based on the outline 13.

The coil 40, which is inserted manually or mechanically, fits into anannular recess which is formed in this way. Also, the chip 42 can befitted into the opening 24 intended for it and can be held in place by aspot of adhesive which can be provided beneath it. Connecting wires 44between coil 40 and chip 42 simply lie on top of the second web 20. Thecoil 40 is fixed in place by the middle spots of adhesive, which havemaintained an adhesive effect when the ring 30 is removed. The result ofthis operation is shown in FIG. 6, the coil 40 being indicated byhatching.

Next, a third web 46 can be guided in register onto the second web. Thethird web 46 may also be provided with adhesive (not shown),specifically in alignment with the spots of adhesive on the first web10. Since the spots of adhesive are arranged symmetrically with respectto a center plane running in the conveying direction, the third web 46may be provided with spots of adhesive on the same installation as thefirst web. The first and/or third webs 10, 46 may be provided with theadhesive while in stock and can then be stored until use, in which casethe adhesive side is protected by a web of separating paper which isknown from labels; the web of separating paper is pulled off before theadhesive bonding takes place and can be reused. It serves as onepossible option for covering the spots of adhesive. The third web 46has, for example, the same thickness as the first web 10, e.g. 0.1 mm.

The pattern of adhesive on the third web 46 may also be selecteddifferently. Furthermore, the third web 46, which performs only aprotective function, may also be omitted. As an alternative, the thirdweb 46 may also serve to accommodate the chip 42, and to this end isthen provided with a chip opening. Furthermore, the connecting wires 44preferably lie in the third web 46.

The assembly which has been joined with adhesive can then be secured byweld spots. It can immediately be processed further to produce finishedcards, for which purpose covering webs 50, 52 are fed in register ontothe outer sides of the first and third webs 10, 46, or of the first andsecond webs 10, 20 if there is no third web 46. For this purpose, thecovering webs 50, 52 have suitable markings which correspond to those ofthe other webs. The layer structure formed in this way is guided througha lamination device, as described, for example, in EP 134 820, in orderto join together the individual webs to form a final web. Then, plasticcards, in each of which a chip 42 with flat coil 40 is embedded, arestamped out of the final web along the outline 13. A section throughpart of a card which has been produced in this way, in the region ofcoil and chip, is shown by FIG. 8.

As an alternative to arranging covering webs 50, 52 on both sides, it isalso possible to provide such a covering web only on one side.

The various webs 10, 20, 46, 50, 52 each consist of a plastic material.Preferred plastic materials are PVC, polycarbonate and polyethylene.

However, it is also possible to produce the assembly of first, secondand, if used, third webs 10, 20, 46 and to keep it in stock on reels. Ifthe diameter of these reels is not less than 300 mm, or even 250 mm, ithas been found, amazingly, that it is not possible to detect any damageto either the coil or its connection to the chip, and therefore thereject rate remains low. The assembly can therefore be produced at onesite and then taken to a lamination installation, where the assembly isthen treated as a standard web, i.e. a web which does not contain a coilwith a chip.

As a modification to the method described above, the middle spots ofadhesive 16 do not have to be applied, i.e. they may be dispensed with.This leads to the-portion which is stamped out, in this case the ring30, not adhering to the first web 10 since it is a separate piece ofweb. Since this stamped-out portion is removed in any case, it ispossible to dispense with this interim fixing. In order to attach theflat coil 40, it is possible, before said coil is put in place, to applyadhesive to the first web 10 in the aperture which is formed by thestamped-out portion. As an alternative, the flat coil 40 may be held inplace by attaching a covering web to the second web 20. The inner andouter spots of adhesive 14, 18 in a region which is close to the flatcoil 40 which is to be accommodated by the aperture ensure that theaperture can be made with the correct dimensions.

FIGS. 9 to 11 illustrate sections of a method of producing plastic cardshaving a chip and a flat coil which is connected to the chip, inaccordance with a second exemplary embodiment. The results of furthermethod steps illustrated in FIGS. 6 to 8 apply correspondingly to thesecond exemplary embodiment, so that to this extent reference may bemade to these FIGS. 6 to 8 in connection with FIGS. 9 to 11.

The second exemplary embodiment differs from the first exemplaryembodiment in that the outer and inner spots of adhesive 14, 18 arereplaced by outer and inner weld spots 15, 19. There are no middlefixing points. Furthermore, there is no outer weld spot 15 where anopening 24 for a chip is provided. An alternative outer weld spot may beadded, or the opening 24 for the chip may be spatially shifted (FIG.10).

According to the second exemplary embodiment, starting from a first web10 in accordance with FIG. 9, which corresponds to the first web 10illustrated and described in FIG. 1, a second web 20 is laid on thefirst web 10 in accordance with FIG. 9, leaving out the method stepillustrated in FIG. 2. Then, outer fixing points 15 and inner fixingpoints 19 are put in place, which fixing points are in this case formedby weld spots, which join the first web 10 and the second web 20together by limited local fusion between the two webs 10, 20. The fixingpoints, in the form of weld spots 15, 19, like the spots of adhesive 14,18, are distributed in such a manner that they are arranged on bothsides next to a part of the web which corresponds to a shape of the flatcoil 40 (FIG. 6).

In a following operation, the result of which is illustrated in FIG. 11,two concentric cuts 26, 28 are made only in the second web, by means ofa stamping tool, preferably by means of a strip steel punch. Thisstamping operation serves to form an aperture in the second web 20 whichwill subsequently accommodate the flat coil 40. Consequently, thestamping for the aperture lies between the outer and inner weld spots15, 19. The statements made with regard to FIG. 4 apply correspondinglyto this stamping operation.

The ring 30, which is delimited by the cuts 26, 28, is then removed fromthe second web 20. To do this, the webs 10 and 20, which are joinedtogether, can be guided over a transverse rod 34, as shown in FIG. 5,with the result that the webs 10, 20 undergo a bending process Thismakes it possible for a stamped-out region to lift up out of the secondweb 20, since this region is not held by fixing points, and to be takenhold of by a hook 38, from which it is then removed by means which arenot shown.

The coil 40, which is inserted manually or mechanically and then restson the first web 10, fits into an annular recess which is formed in thisway. The chip 42 may also be inserted into an opening 24 intended forthis chip and may be held in place by a spot of adhesive which may beprovided beneath it. Connecting wires 44 between coil 40 and chip 42simply lie on top of the second web 20. The coil 40 may be fixed inplace by a spot of adhesive which may be provided on the first web 10.As an alternative, the coil 40 may be held in place by a covering web,as is provided, for example, as web 46 and/or 50 in accordance withFIGS. 7 and 8 and has maintained an adhesive effect when the ring 30 isremoved. The result of this operation is illustrated in FIG. 6, the coil40 being indicated by means of hatching.

The weld spots 15, 19 may, for example, be applied by ultrasonicwelding.

Otherwise, the statements made in connection with the first exemplaryembodiment apply correspondingly.

What is claim is:
 1. A method of producing plastic cards with a layerstructure, in each of which cards a flat coil and a chip which isconnected thereto are embedded, these components being placed on a firstweb, to which a subsequent web for accommodating apertures for thecomponents and at least one covering web are applied, which webs arethen joined together by lamination so as to form a final web, out ofwhich plastic cards are stamped, wherein a second web, which is placedon the first web, is held on a selectable web section of the latter bymeans of fixing points, while an aperture which is to accommodate theflat coil is made in the second web, for which purpose the fixing pointsare distributed in such a manner that they are arranged on both sidesnext to a part of the web which corresponds to a shape of the flat coil,and then the flat coil, in order to be placed on the first web, isinserted into the aperture formed in this way and the chip is insertedinto a web which is provided with a chip opening.
 2. The method asclaimed in claim 1, wherein spots of adhesive are used as the fixingpoints.
 3. The method as claimed in claim 1, wherein firstly middlespots of adhesive, which are distributed so as to match a shape of theflat coil, are applied to the first web, and the fixing points, in theform of outer and inner spots of adhesive, are applied next to thesemiddle spots of adhesive on both sides.
 4. The method as claimed inclaim 3, wherein the flat coil is fixed on the first web by means of themiddle spots of adhesive.
 5. The method as claimed in claim 2, whereinthe adhesive is applied by the screen printing process.
 6. The method asclaimed in claim 2, wherein that side of the first web which is providedwith spots of adhesive is provided with a cover until it is processed.7. The method as claimed in claim 1, wherein weld spots are used as thefixing points.
 8. The process as claimed in claim 7, wherein, in orderto apply the weld spots, firstly the second web is laid on the firstweb, and then the weld spots are applied by locally fusing together thewebs lying one above the other.
 9. The method as claimed in claim 8,wherein the weld spots are applied by ultrasonic welding.
 10. The methodas claimed in claim 1, wherein the flat coil is fixed on the first webby applying a covering web to the second web.
 11. The method as claimedin claim 1, wherein the fixing points are spaced apart from one anotherin such a manner that in each case three to six fixing points of thisnature are distributed circumferentially on both sides next to the shapeof a flat coil.
 12. The method as claimed in claim 1, wherein the webwhich is provided with the chip opening is formed by the second web. 13.The method as claimed in claim 1, wherein the chip is fixed by means ofadhesive beneath the chip opening.
 14. The method as claimed in claim 1,wherein the aperture for the flat coil is made by stamping out a part ofthe web which corresponds to the shape of the flat coil.
 15. The methodas claimed in claim 1, wherein, in the event that a toroidal coil isused as the flat coil, the fixing points which are arranged on bothsides are in each case arranged radially behind one another.
 16. Themethod as claimed in claim 1, wherein the aperture is stamped out bymeans of a strip steel punch.
 17. The method as claimed in claim 1,wherein a semifinished product which is formed by the first and secondwebs, after the stamping, is curved about an axis which runstransversely to the extent of the web, and the ring, which consequentlybecomes partly free, is taken hold of and removed.
 18. The method asclaimed in claim 1, wherein, when the second web is being perforated toproduce an aperture for the flat coil, a receiving opening for the chipis also made.
 19. The method as claimed in claim 1, wherein the webs areprovided at their edges with equidistant markings which are used toguide the individual webs together so that they are in register.
 20. Themethod as claimed in claim 1, wherein a printed web is used as at leastone covering web.